In general, a device such as an automatic transmission, a hybrid drive device, or an engine that is mounted in a vehicle is subjected to lubrication and cooling using oil and, depending on the configuration of a device, to hydraulic control using oil. To collect and store oil used for such purposes, an oil pan is provided below the device, for example. The oil pan is attached to the device in such a manner that a gasket made of rubber or the like for sealing oil is interposed between the oil pan and the device, and the oil pan is fastened to the device with a plurality of bolts (see Patent Document 1).